The Missouri–Kansas–Texas Railway (reporting markMKT) is a former Class I railroad company in the United States, with its last headquarters in Dallas. Established in 1865 under the name Union Pacific Railway, Southern Branch, it came to serve an extensive rail network in Texas, Oklahoma, Kansas, and Missouri. In 1988, it merged with the Missouri Pacific Railroad and is now part of Union Pacific Railroad.

In its earliest days the MKT was commonly referred to as "the K-T", which was its stock exchange symbol; this common designation soon evolved into "the Katy".

The Missouri, Kansas & Texas Railway was incorporated in May 1870 in Junction City, Kansas. Ostensibly the original goal of the company was to build a supply railroad connecting the frontier military bases of Fort Riley, Fort Gibson and Fort Scott; and eventually Fort Worth; although its broader ambitions were to also connect to Chicago and New Orleans.[1] Upon its incorporation the MK&T acquired the Union Pacific Railway, Southern Branch (est. 1865) and its 182 miles (293 km) of track in Kansas. (Union Pacific Railway was, for a period of several years in the late 19th century, the official name of the unrelated Union Pacific Railroad, which later acquired MKT as part of the Missouri Pacific Railroad.)

At the time of its 1870 incorporation, consolidations were also made with the Labette & Sedalia Railway Co. and the Neosho Valley & Holden Railway Co.; MK&T also acquired the Tebo & Nosho Railroad Co., the St. Louis & Santa Fe Railroad Co., and the Hannibal & Central Missouri Railroad Co. Combined with the UP Southern Branch, these small, newly built railroads formed the foundation on which the Katy would build.

Congress had passed acts promising land grants to the first railroad to reach the Kansas border via the Neosho Valley. The Katy portion of the former UP Southern Branch, which had begun building from Fort Riley just north of Junction City, Kansas, was in a heated competition for the prize. On June 6, 1870, Katy workers laid the first rails across the Kansas border, winning the race. Congress' promised land grants were never made, as the courts overturned the grants because the land was in Indian Territory and was the property of the Indian tribes.

The Katy continued its push southward, laying track through the territory and reaching Texas in 1872, acquiring other small railroads while extending its reach to Dallas in 1886, Waco in 1888, Houston in April 1893 and to San Antonio in 1901.

In 1896, as a publicity stunt set up by William Crush, the Katy crashed two locomotives head-on, pulling loaded trains, at a site that came to be known thereafter as Crush, Texas. The collision occurred before more than 40,000 spectators, three of whom died (and several were injured) by debris from the exploding boilers. The ragtime composer and pianist Scott Joplin, who was performing in the area at the time, commemorated the event in his song "The Great Crush Collision March" (which he dedicated to the Missouri-Kansas-Texas Railway).[3]

In 1997 the segment linking Katy, Texas to downtown Houston was abandoned, and stripped of rails soon after. The section between Katy and Interstate 610 was purchased by the Texas Department of Transportation in 1998 for the expansion of Katy Freeway. The line that went into Houston was purchased by the city's Parks and Recreation Department. In 2009 it was adapted and paved as the Heights Bike Trail.

As part of a new heritage program, in July 2005 Union Pacific unveiled a new EMD SD70ACe locomotive, Union Pacific 1988, painted in traditional MKT colors.

1870–1880s, Early steam locomotives were dark maroon, with large oval medallion on the side and back of the tenders, with a field of Chinese vermillion and the letters M. K. & T. R. W. inside the oval and on the side of the crew cab, a one and one-half inch gold line on the outer edge, and the number of the engine in the center of field in gold, black shaded and split on the rear of the tender. All passenger engines were finished with gold lettering and striping.[8][9] Rolling stock used colors common in those days, i.e. boxcar brown, caboose red, etc.

1880s–1900s, Steam locomotive livery was simplified after Jay Gould gained control of the railroad. Gould instructed shop personnel to paint all engines black and place the railroad initials M. K. & T. in about 12 inch letters on the side of the tender tank bordered by half inch striping. The engine number was placed on side of the crew cab, side of the sand dome, coping of the tender and back of tender.[10] Rolling stock used colors common in those days, i.e. boxcar brown, caboose red, etc.

1900s–1923, Steam locomotive livery was simplified to overall shiny black, dark graphite smokebox, smokebox door and stack. The color of all lettering and numbers was changed to white. The road name, M. K. &. T. was moved to the side of the crew cab, along with the engine number. The engine number was painted on the side of the tenders in large numerals and on the rear in smaller numerals; the number remained on the sand dome.[11] Rolling stock used colors common in those days, i.e. boxcar brown, caboose red, etc.

1928–1947 Steam locomotives were shiny black with the MKT herald on their tenders. Rolling stock used colors common in those days, i.e. boxcar brown, caboose red, etc.

1947–1957, Diesels were bright red with silver side panels and cream yellow on top of the nose hoods. Passenger cars were painted to match. Boxcars, cabooses, and other rolling stock were frequently painted Sloan Yellow (named for MKT President Matthew S. Sloan).

1957–1965, Diesels were painted an inferior red (known as Deramus red) which quickly oxidized with yellow road numbers. The Deramus era herald was an elongated version of the original style but changed to read simply "Katy" in red letters on a gold background. The text and herald were outlined in black.

1965–1971, The Katy returned to a bright red paint (known as Barriger red), perhaps deeper than that used 1947-1957. They also returned to the original shaped herald but still read "Katy".

1971–1988, Diesel locomotives, cabooses, and other rolling stock were painted green with yellow stripes, lettering and numbering. The first Katy locomotive painted into this scheme was GP7 #123.

In its final years, the Katy acquired several locomotives second-hand which, due to its impending acquisition by Union Pacific, were not painted into the standard green and yellow scheme. MKT acquired 18 GP40s from Conrail in late 1983 that were numbered 231-248.[12]

A set of nine GP39-2s were acquired from Kennecott Copper Corporation in late 1984. Ex KCC #779-783, 785, and 787-789 were renumbered MKT #380-388.[13]

In 1985, three additional GP38s were purchased from Conrail that were numbered 322-324 and finally, 19 GP38ACs were purchased from Illinois Central Gulf and numbered 325-343.[14]
The changes in MKT's red paint were most likely due to problems with fading in the intense Texas sun. This may also have been the reason to change to green in 1970.